Train-control device



June 26, 1928. 1,674,761

E. s. COOK TRAIN CONTROL DEVICE Filed July 25, 1927v MAIN RES.

EQUALIZING I51 RED. RES.

Z RED. RES.

EARLEsco oK k ATTORNEY Patented June 26, 1923.

warren stares EAR-LE S. COOK,

or WILMERIDING, PENN SYLVANIA, ASSIGNOB TO THE WESTING- HOUSE A113 BRAKE COMPANY, OF WILMEEDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

TRAIN-CONTROL DEVICE.

Application filed July 23,

This invention relates to automatic train control apparatus and more particularly to that type having means for automatically eiiecting a brake pipe reduction in two stages. y

In the pending application of Thomas H. Thomas and Earle S. Cook, Serial No. 109,044, filed May 14, 1926, means are dis closed for automatically effecting a. split or two stage reduction in brake pipe pressure, whenever the train control apparatus operates to make a brake application on the train.

lVhether or not a two stage reduction in brake pipe pressure is required for applying the brakes on a train, is mainly dependent upon the train speed. It the train speed is low, the retarding force on the train, caused by applying the brakes, developes much more rapidly than it the train speed is high, so that as a result, when the train speed is high, the brakes may be applied by effecting a single and full reduction in brake pipe pressure, without causing any damage to the train.

The principal object'of my invention is to provide means for automatically preventing the split reduction device "from effecting a two stage reduction in brake pipe pressure, in case the brakes are automatically applied by a change in signal indication, when a train is operating in territory governed by a high speed .'.g1ial indication.

In the accompanying drawing, the single figure is a diagrammatic view of a train control apparatus, embodying my invention.

As shown in the drawing, the apparatus may comprise a speed governor device 1, a speed valve device 2, an application. valve device 3, and equalizing piston device 4, a medium speed magnet valve device 5, a high speed magnet valve device 6, and a split reduction valve device.

The speed governor device 1 comprises a governor 7 of the usual centrifugal type, adapted to be rotated according to the train speed and in operation is adapted to cause movement of a crosshead 8, carrying a plurality of tappets adapted tooperate corresponding valves at various train speeds, such as a medium speed application valve 9 and a. low speed application valve 10.

The speed valve device 2 comprises a hi in speed piston 11 contained in a chamber 32 1927. Serial No. 207,840.

and a slide valve 13 contained in a chamber 14 and adapted to be operated by said piston, which piston is opposed in outward movement by the pressure of a coil spring 15. Said speed valve device further comprises a medium speed piston 16, contained in a chamber 17, and tained in the chamber 14 and adapted to be operated by said piston. The piston 16 is opposed in outward movement by the pressure of a coil spring 19, contained in the piston chamber 17.

The application valve device 3 comprises a casing having a chamber 20, containing a piston 21 and a chamber 22 containing a slide valve 23, adapted to be operated by said piston, which piston is opposed in outyvlp-rd movement by the pressure of a spring The equalizing piston device 4 comprises an equalizing piston 25 a chamber 26 connected .to the usual equalizing reservoir 27 through pipe 28 and at the opposite side a chamber 29 connected to the usual brake pipe 3O. Said piston is adapted to operate a brake pipe discharge valve 31 for venting fluid under pressure from the brake pipe to the atmosphere.

The medium speed magnet valve device 5 comprises a magnet and valves 32 and 33, operable by said magnet. The high speed magnet valve device 6 comprises a magnet and valves 34 and 35, operable by said magnet.

The split reduction. valve device is similar to that disclosed in the pending application of Thomas H. Thomas and Earle S. Cook, Serial No. 109,044, filed may 14, 1926, and comprises a control portion 36 and a hold-back portion 37. Thecontrol portion 36 comprises a piston 38 contained in a chamber 39 and apiston 40 contained in a chamber 41, said pistons having diflerent areas, being connected together by a stem and being adapted to cooperate in operating a slide valve 42. contained in a chamber 43, formed intermediate said pistons. The hold-back portion-37 comprises a piston 44, contained in a chamber 45, and a slide valve 46, contained in a chamber 47 and adapted to be operated by said piston. Inward movement of said piston and slide valve is opposed by the pressure of a coil spring 48 against thrust Washer 49, tile a slide valve 18 C011.

forming, at one side,

of the piston stem.

Said spring and Washer are containedin achamber 86 connected to the atmosphere through a passage'it in the casing and connected to the valve chamber i7 through openings 88 formedin the piston guidev portion 87.

in operation, fluid under pressure is supplied from a main reservoir 50 =to a feed.

valve device 51, which is adapted to reduce the pressure of said fluidito. that employedin.

the brake pipe 30 and in the operation of the traincontrol apparatus.- Fluid at said reduced iprcssure .is supplied from said ieed valve device to. pipe 52, from whence it flows to the speed" valvel chan'iberl4; the

applicationvalve chambertolthe seat of.

the application slide valve 23-.and tothechambers containing the magnet valves and 35 l Vith the application slide valve 23 inreleaseposition; as shownin the draw? ing, cavity 53' therein registers with passage 52, so that fluid from said passage flows through the cavity 53 to the brake pipe 30,. charging said brake pipe and i'rom' said cavity also through passage andg'pipe 54 to chamber26' ot'the equalizing pistoh device 4l andirom said chamber to the equalizing y w reservoir 2n through pipe 28. lluid under pressure is supplied from the brake pipe 30 to the equalizing piston chamber 29. The fluid pressures thus being equal on the op posite sides of the equalizing piston25, the.- Brakeplpe dlscharge valve 31 is heldseatedi fluid being suppliedto the control piston chamber 41 of thesplit reduction device, the control pistons 38 and 40 and slide-valve 42are'heldintheir upper position, as shown in the drawing, since the cont-rol piston chamber 39 is norn'ially vented to the atmospherethrough pipe and passage and the atmospheric choke plug 56. With the control portion 37 of thesplit reduction device in thispositioin the piston chamber-45 of 37 1s vented to theatmosphere through passage and pipe 57 the holthhack portion cavity 58 in the control portion slide valve 4:2'andlthe, choke plug59, "sothat the pressure otsprii1g 4 8 holds the holcl baok piston 44 and'svli'de valve 46 in the position shown in the drawing in which position a first reduction reser-voir- 60 is. connectedto a second reduction reservoir 61, through pipes and passages 62 and; 63 and a cavity Gtl'ormedj in the hold-back slide valve 416. With the applicat passages 62 and-'63, cavity 65 in the application slide valve and-an atmosphericexhaust passage 66;

When a train is operating in territory governed by a high tion, the magnetotthe high speed ma 'g'net valve device 6 energized and holds he valve 34 seated and the valve 35 unseated,

ion slide-valve. in releasep os1tion,sa1'd reduction reservoirs are both vented to the atmosphere through pipes and speed signal indica- \vhile themagnet of the medium speed mag netiv a-lvedeviceo is deenergized, so that the valve. 32'is unseated and the valve 33 seated. With the high speed magnet valve 34' seated and the valve35 unseated, fluid at teed valve pressure flowsfromthe chamber containing the valve 35 to the high speedvalve piston chamber 12.- The fluid pressure thus be comes equal on the opposite sides of the li'iglnspeed piston 11, and. the pressure of spring 15 holds said piston and the slide valve 13 initheposition shown in the drawing, in. which, a. port 67 through the slide valve-=13 registerswith apassage 68 in the seat,- tlnoughivhich fluid is supplied tothe medium speed piston chamber 17. The fluid pressure thusbecoines equal 5 on the opposite sides of themedium speed piston 16, so that the-pressure nit-the coil'spring 19 will hold said piston. and-the slide valve 18in the position-shown in the drawing.

Eith the high speed'slide valve 13in the inner position fluid under. pressure is sup-. plied from the valve chamber 14 to the. apq plication piston chamber 20 through the passageuandpipe 70.. Fluidunder. pressure oif'said application.piston 21: becomes equalized'and the pressure of spring 24. holds said piston: and the slide valve 23 in the release-position, as shown in the drawing.

Withthe control. pistons. and. 410 and slide valve 412 of the split reduction device in the upper position aItiming:reserrwoir Tl ventettto the atmosphere tl'iroi-igh pipe and passageTZ, pasta ball check valve 73 and through v the atmospheric choke plug 59; 4 The chamber 47: of: the hold-back portion-oft the split reduction device is open to the atmosphere by Way/otthe opening 88 through the piston guideSi" and. chamber 86; which is providedvvith an atmospheric vent port: 74, and since in the positiondcscribed; passage '72: isopen. to chamber 47, thetiming reservoir. 71 is also. vented to theatmosphere by Way of. port. 74.

If the signal indication changes from high speed tO-ll'lGfilillll]. speed, the high speed magnet becomes deenergized, thereby peropposite sides;v

I (if) ill) 1 tion,-in which, the hold back when the speed of the train exceeds the medium speed limit. The-application piston chamber is thus vented to the EttIl'lOSPhClQ, which permits the fluid pressure in the application valve chamber 22 to shift the application piston the outer or application position.

\Vith the application slide valve 23 in application position, the supply of fluid at feed valve pressure to the brake pipe 30, to the equalizing piston chamber 26, andto the equalizing reservoir 27 is cut off and the brake pipe is lisconnecte'd from said piston chamber and reservoir. The atmospheric vent of the first and second reduction reservoirs 60 and 61, respectively,through cavity 65 is also cut OH and the equalizing reservoir 27 and equalizing piston chamber 26 areconnected to the first reduction reservoir 60 through pipe and passage 54, cavity 65 in the slide valve and passage and pipe 62 Fluid under pressure from the equalizing reservoir 27 then flows to the first reduction reservoir 60, causinga reduction in equaliz ing reservoir pressure. The equalizing piston device 4 then'operates in the well known manner to cause a corresponding reduction in brake pipe pressure. The fluid discharged from the brake pipe by the equalizing piston device 4 is vented into passage 55 and then to the. atmosphere through the atmospheric choke plug 56. The capacity of said choke plug is less than the rate of flow past the opened discharge valve 31, so that a pressure builds up in passage 55. Since said passage is connected to the control piston chamber 39, a corresponding pressure is built up therein .and acts to shift the control pistons 38 and and slide valve 42 to the downward posipiston chamber is connected through passage and pipe 57 and cavity 58 in the slide valve 42, to passage and pipe 81 leadingto the seat of the medium speed slide valve 18.

Vith the high speed slide valve 13 in the outward. position, a cavity 7 8, therein, connects passage 68 from the medium speed piston chamber 17 to passage and pipe 79 leading to the medium speed magnet valve device 5. Since the magnet of said device is energized in territory governed. by a medium speed signal indication, the valve 32 is seated and the valve 33 is unseated, so that fluid under pressure from pipe 52 is supplied to the medium speed piston chamber 17 through pipe and passage 79, cavity 78 in the high speed slide valve 13 and passage and pipe 68, thereby maintaining the medium speed piston .16 and slide valve 18 in the inner position, in which position, a cavity 80,.t-herein, connects passage and pipe 81 from the split reduction device to the atmospheric passage 82. Since the hol lback piston chamber 45 is connected to the 21 andslide valve 23 to passage 81, when the control pistons 38 and 40 and slide valve 42 are in the downward position,said piston chamber 45 is maintained at atmospheric pressure during the first reduction in brake pipe pressure. The pressure of spring 48 therefore holds the holdback piston 44 and slide valve 46 in the position shown in the drawing, in which, the first and second reduction reservoirs and 61 are connected, so that the fluid from the equalizing reservoir flows to both of said reduction reservoirs and causes a continuous and complete service reduction in the equalizing reservoir pressure.

If a train is operating above a low speed limit in territory governed by a medium speed signal indication, the governor medium speed valve 9 is seated, thereby prevent ing the venting of fluid from the application piston chamber 20, and the governor low speed valve 10 is unseated. indication then changes to a low speed, the magnet of the medium speed valve device 5 becomes deenergized and the magnet of the high speed magnet valve device 6 re mains deenergized, as in territory governed by a medium speed signal indication. Deenergization of the first mentioned magnet permits valve'33 to seat and valve 32 to be unseated, which'permits a venting of the fluid under pressure from-the medium speed piston chamber 17, by way of passage 68, cavity 7 8 in the high speed slide valve 13 and pipe and passage 79.- The fluid pressure in the speed valve chamber 14 then shifts the medium speed piston 16 and slide valve 18 to the outward position, in whicln the application piston chamber 20 is vented to the atmosphere through passage '70, cavity 83 in the medium passage and pipe 84 and past the unseated governor'valve 10. The application piston 21 andslide valve 23 are then shifted to the outeror application position and an application of the brakes is initiated in the same manner as hereinbefore described.

.In the outward position of the medium speed slide valve 18, the cavity in said slide valve connects passage 52 from the feed valve device 51 to passage 81 leading to the seat of the control slide valve 42 of the split reduction device, so that when the control pistons 38 and 40 shift the slide valve 42 to the downward position, upon initiation of the first reduction, fluid under pressure from passage 81 is permitted to flow through cavity 58 in said slide valve and passage 57 to the hold-back piston chamber 45 and shift the hold-back piston 44 and slide valve 46 t0 the inner position and thus disconnect the passages 62 and 63 from the first and second reduction reservoirs 60 and 61, respectively, so that the degree of the first reduction in equalizing reservoir pressure will be limited. to the If. the signal speed slide valve 18,

' first, reduction reservoir.

. Fluid underpressure supplied to passage and pipe 57 leadingto the hold-back piston chamber 4-5 also flows from said pipe through a choked passage 89 and pipe and passage 72 to the timing reservoir 71, and since passage 72 lromthe timing reservoir is lapped in the innerposition, said reservoir becomes charged.

When the first reduction in brake pipe pressure is completed and .:the discharge valve '31 is seated, the fluid under pressure from the control piston chamber 39 is then vented to the atmosphere through pipe and I passage '55and the choke plug 56. Theron trolv pistons 38 and 40 andslideyalve 42 are then shifted to their upper-position, by the brake pipe pressure in chamber 41, in which position the hold-back piston chamber 45 and the timing reservoir 71 are connected to the atmosphere through pipe andfpassage 57 cavity 58 in the slide valve 42 and the atmospheric chokeplug59. lVhen the pressure of the fluid acting on the hold-back piston 4-5 is thereby reduced to a predetermined degree, the pressure or spring 48 shifts said piston and the slide valve 46 to the position shoWn in; the drawing, in Which position the cavity 64 in said slide valve connects the passages 62 and 6 3 leading to the first and second reduction reservoir 60 and 61 respectively. The fluid under pressure in the equalizing reservoir 27 and first reduction reservoir 60 then equalizes into the-second reduction reservoir 61, causing a further predetermined decrease in said equalizing reservoir pressure. Since the pressure in chamber 26 or the equalizing piston device 4 also reduces a correspond ing degree, said device then operates to cause a corresponding second reduction inthe pressure of the brake pipe fluid. I

During the second reduction, the holdback portion 37 ofthe split reduction device is preventedfrom operating to again sepa rate the two reduction reservoirs and there by interfere with the second reduction, on account of the control pistons and slide valve being heldin the upper positionby the pres sure of fluid from'a lock-up reservoir "95, which is connectedto the valve chamber 43 through pipe and passage and cavity 91 in the slide valve 42, said loclz-'upi reservoir becoming charged, While effecting the lirst reduction, by fluid under pressure from. the brake pipe, Which fluid flows thereto through passage 30, cavity 92 in the application slide valve 23, pipe and passage 93, cavity 94 in the controlslide valve 42 of the split reduc tion device, and passage and pipe 90.

If a train is running above the medium speed limit in territory-governed by a high speed signal, indication and the signal incliby the liolcl-baclr slicle valve 46.

cation changes to a low speed,the magnet even though the medium speedslide valve l8 isinthe outer position, because the :fluid under pressure that flows from the feed; valve device through pipe 52 to port 85 1n the medium" speed slide valve 18 is vented to the atmosphere through the open governor valve 9, by Way ofpassage .and pipe 'Z' T, instead ofbeing-permitted toflow .to thesplitreduction device through passage and pipe 81-. If, however, a train is runningbelowl a mediumspeed limit in territorygoverned by a high speed signal indication and the. signal indication changesto 'loW speed, a split or twolstag'e reduction is'obtained in the same manner as when a brake application is effected onv a train by a change from a medium speed signal indication to a low speed signal indication, since below medium speed the governorvalve 9is seated, so that the fluid supplied to passage and pipe 81, through port 85 'infthe medium speed slide valve 18, flows-to the split reduction device Whiclrthen operates .inithe manner hereinbetfore, described.

Having noW described my invention, What I claim as-neW and desire'tosecure by Let ters Patent, is I 1.. In an automatic train control apparatus, thecombination with a brake pipe, of a timing reservoir, a valve device subject tothe pressure in said reservoir for initiating. a two stage reduction in brakepipepressure, and a valve device operated according to the signal indication for supplying fluid under pressure to said reservoir in one ,posireservoir to the tion and for venting said atmosphere 1n another position.

cause the appli 2.111 an automatic train control apparatus, the-combination with a brakepipe, of a timing reservoir, a valve device subject to, the pressure in said reservoir, for initiatingatwo stage reduction in sure,'and a valve device operating When the signal indication is for highspeed for venting said reservoir 'to the atmosphere and when thesignal indication is for a lower speed for supplying fluid under pressure to said reservoir. I i

3. In an automatic train control apparatus, the combination with a brake pipe, of a timing-reservoir, a valvedevicesubject to thepressure in said reservoirflfor initiating a tWo stage reduction in. bralzepipe pressure, and a valve device operating-When the signal indication is for high speedfor venting said reservoir to the atmosphere and when the signal indication is for low speed for supplying fluid under pressure to said reservoir.

4:. In a fluid pressure brake, the combination with a brake pipe, of a valve device operated by an increase followed by a decrease in fluid pressure for initiating a two stage reduction in brake pipe pressure, and means operated when the signal indication is for a high speed for preventing an increase in pressure on said valve device and when the signal indication is for a lower speed for supplying fluid under pressure to said valve device.

5. In a fluid pressure tion with a brake pipe,

brake, the combinaof a valve device operated loy an increase followed by a decrease in fluid pressure for initiating a two stage reduction in brake pipe pressure, a valve means normally connecting said valve device to the atmosphere and operated by V in making a first reduction in brake pipe pressure for connecting said valve device to a passage, and a valve mechanism controlled by the signal indication and having one position in which said passage is connected to the atmosphere and another position in which said-passage is supplied with fluid under pressure.

In testimony whereof I have hereunto set my hand.

i EARLE S. COOK.

fluid discharged 

